Synchronization of chaotic oscillators has many aspects [1]},
one generally distinguishes complete, generalized, and phase synchronization.
The latter property is related to chaotic oscillators with well-defined phases.
Many chaotic oscillators, like the Rössler system, possess chaotic amplitudes, while
the phase in such systems is not chaotic and corresponds to a zero Lyapunov exponent.
The dynamics of the phase is of diffusion type, and correspondingly the phase synchronization
phenomena for such oscillators are close to those for periodic oscillators with
a certain level of noise in the phase dynamics.
